EmilStenstrom
6 hours ago
I somehow find the concept of a general time series model strange. How can the same model predict egg prices in Italy, and global inflation in a reliable way?
And how would you even use this model, given that there are no explanations that help you trust where the prediction comes from…
teruakohatu
6 hours ago
What is not generally understood is that these models don’t predict egg prices or inflation in Italy.
They decompose a time series into trends, seasonality and residuals. That’s what they are actually modelling.
They cannot predict wars in the Middle East influencing inflation unless there is a seasonal pattern(s).
jcelerier
an hour ago
> They cannot predict wars in the Middle East influencing inflation unless there is a seasonal pattern(s).
well...
lordgrenville
3 hours ago
That's what traditional time-series modelling does. This is a foundational model, which means it's just a neural network trained on lots of time series. (So maybe OP's question still stands? But it's the same question as "how can LLMs be good at so many different kinds of conversations?")
dist-epoch
36 minutes ago
Because traditional time-series modelling (ARIMA, GARCH, ...) is too "simple" and "strict". Just like "simple" computer vision (OpenCV, edge-detection, ...) was crushed by neural networks when having to deal with real world images.
cybrox
5 hours ago
Wars in the middle east seem to have increasingly regular patterns tied to stock market opening hours, unfortunately.
jofzar
4 hours ago
I mean it's super obvious, it's directly tied to scrubs popularity.
New season of scrubs = new war in the middle east.
FartyMcFarter
3 hours ago
Wow, I didn't know. Thank you! Such a great show.
rubyn00bie
5 hours ago
I totally agree with the sentiment but from what I can tell, I’d say they tend happen immediately before or after markets open and close. Essentially, and to their maximum, screwing absolutely everyone who isn’t in the clique from participating in the trade.
FWIW— the only sure fire way to win the trade is to buy time and assume both gross incompetence and negligence when it comes action. The only caveat is if the markets tank enough, this administration will signal capitulation before hand, e.g. Trump mildly capitulating on tariffs last April after the markets proceed to relentlessly defecate themselves.
0-DTE options are typically, and for good reason, stupid gambles. But, right now they can’t even be considered gambling, because there’s zero chance of winning. Not just bad odds, but no odds. Again just signaling how truly malicious this admin is and its disdain for anyone and everyone not close to them.
perks_12
4 hours ago
I am not familiar with time series models, but judging from your answer, it would be necessary to feed long time series into this model for it to detect trends. What is a token here? Can it, for the lack of a better example, take in all intraday movements of a stock for a day, a week, a month, etc?
teruakohatu
4 hours ago
I tend to avoid time series forecasting when I can help it because I find it hard to communicate to stakeholders that a neural network (or another method) is not an oracle.
If you are talking about granularity of observations, it would depend on what you are trying to predict (the price in an hour or the price in 12 months?) and how quickly you need the prediction (100ms? Tomorrow morning?). If I had infinite data I would use granularity as a hyper parameter and tune that to a level that produced the best test results.
I am for example currently using weekly averages for non-price data forecasting. I could use daily data but weekly is absolutely adequate for this purpose.
ghywertelling
16 minutes ago
You can use lightgbm with appropriate feature engineering.
amelius
2 hours ago
What makes these models different from models used for e.g. audio?
Or other low-dimensional time domain signals?
graemep
3 hours ago
Do these models predict on just a single time series then?
it is far more useful for predictions to look for correlations between time series. This is far more complex than looking for correlations in general because most time series trend up or down and therefore correlate.
visarga
5 hours ago
ARIMA and ARMA models
ReptileMan
4 hours ago
It is the Middle East. Wars are always in season. And supply is more than the demand.
d--b
5 hours ago
The main issue is that people do use them to predict bitcoin prices intraday and that sort of things.
nico
5 hours ago
Is it an issue because it works, or because it doesn’t? Or because it’s bitcoin?
I genuinely want to know. Thank you
d--b
4 hours ago
It is an issue because bitcoin is highly unpredictable.
These tools are good at predicting timeseries that are in fact quite predictable. Like insurances will use this to estimate the number of people who will die from cancer in the next year, the year after that, and so on up to 50 years in the future. The model will extrapolate the progresses made in cancer treatment from the current trend, etc. It is a prediction, cause it's still possible that a breakthrough comes in and suddenly people don't die from a certain form of cancer, but generally it should be roughly correct.
Bitcoin prices are a lot more chaotic, influenced by a ton of unrelated events that shape its path a certain way. There is absolutely no certainty that studying the shape of its past evolution will help in any way understand its future evolution.
Of course here I mean by studying its price alone. If you add more information, like who's behind each trend and why, you have a much better sense of what could happen next.
lovelearning
5 hours ago
My understanding is that the synthetic training data helps capture abstract time-series patterns that are common in all domains.
As they say in appendix 8:
> We create the synthetic data to reflect common time-series patterns using traditional statistical models. We start with four simple times series patterns:
> • Piece-wise linear trends (I), where the number of the piece-wise linear components is randomly chosen between 2 and 8.
> • ARMA(p, q) (II), where 1 ≤ p, q ≤ 8 and the corresponding coefficients are generated from either a multivariate Gaussian or a uniform, then normalized.
> • Seasonal patterns. In particular we create the sine (III) and the cosine (IV) waves of different random periods between 4 and max context length / 2 time-points and time delays.
If there were no such underlying patterns in the class of all time-series data, then even the idea of traditional time-series models would be fundamentally misplaced.
And since this is a transformer model, it also looks for patterns in the problem-specific input data at inference time, just like how the input context to an LLM influences its output's relevance.
JackeJR
an hour ago
Actually it can. See https://youtu.be/FUQwijSDzg8?si=LWd5gVNYRd3HH9rJ
Or just search for the James-Stein paradox.
annie511266728
3 hours ago
It’s not really predicting “egg prices” or “inflation” — it’s mostly fitting patterns that happen to show up in those series.
The problem isn’t domain generalization, it’s that we keep pretending these models have any notion of what the data means.
People ask how one model can understand everything, but that assumes there’s any understanding involved at all.
At some point you have to ask: how much of “forecasting” is actually anything more than curve fitting with better marketing?
fjdjshsh
an hour ago
"curve-fitting" has a long history (centuries old) and could be regarded more as a numerical method issue.
Rigorous understanding of what is over fitting, techniques to avoid it and select the right complexity of the model, etc, are much newer. This is a statistical issue.
My point is that forecasting isn't curve fitting, even thought curve fitting is one element of it.
eru
5 hours ago
> How can the same model predict egg prices in Italy, and global inflation in a reliable way?
How can the same lossy compression algorithm (eg JPG) compress pictures of everything in a reliable way?
cenamus
5 hours ago
It can't compress pictures of everything in a reliable way.
Text and anything with lots of high frequency components looks terrible
eru
3 hours ago
It still doesn't pretty well on text. And we have newer formats and ideas that would also deal with that. (To be really dead simple: have a minimal container format that decides between png or jpg, use png for text.)
However: white noise is where it really struggles. But real pictures of the real world don't look like white noise. Even though in some sense white noise is the most common type of picture a priori.
Similar for real world time series: reality mostly doesn't look like white noise.
FartyMcFarter
2 hours ago
White noise is random, so it's incompressible by definition. By JPG or by any other method no matter how clever.
eru
2 hours ago
I have a very peculiar coin. With 1% probability it turns up heads and with 99% probability it turns up tails.
A string of flips is random, but it's very compressible.
In any case, my point was that reality ain't uniformly random. And not only that: pretty much anything you can point your camera at shares enough similarity in their distribution that we pretty much have universal compression algorithms for real world data.
at_compile_time
4 hours ago
Reliably terrible.
benob
6 hours ago
I would say:
- decomposition: discover a more general form of Fourrier transform to untangle the underlying factors
- memorization: some patterns are recurrent in many domains such as power low
- multitask: exploit cross-domain connections such as weather vs electricity